From 6ab1b829a084005dbad747c3f31af2411107585c Mon Sep 17 00:00:00 2001
From: Roman Nozdrin <roman.nozdrin@mariadb.com>
Date: Mon, 12 Oct 2020 15:20:49 +0000
Subject: [PATCH] MCOL-4334 Enable Select Handler for queries run inside Stored
 Procedures

There is another session variable to enable/disable SH in SP
---
 dbcon/mysql/ha_mcs_pushdown.cpp |  9 ++-------
 dbcon/mysql/ha_mcs_sysvars.cpp  | 20 ++++++++++++++++++++
 dbcon/mysql/ha_mcs_sysvars.h    |  3 +++
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/dbcon/mysql/ha_mcs_pushdown.cpp b/dbcon/mysql/ha_mcs_pushdown.cpp
index ca6d52a11..450424c01 100644
--- a/dbcon/mysql/ha_mcs_pushdown.cpp
+++ b/dbcon/mysql/ha_mcs_pushdown.cpp
@@ -747,13 +747,8 @@ create_columnstore_select_handler(THD* thd, SELECT_LEX* select_lex)
 
     // Check the session variable value to enable/disable use of
     // select_handler
-    if (!get_select_handler(thd))
-    {
-        return handler;
-    }
-
-    // Disable SP support in the select_handler for now.
-    if ((thd->lex)->sphead)
+    if (!get_select_handler(thd) ||
+        ((thd->lex)->sphead && !get_select_handler_in_stored_procedures(thd)))
     {
         return handler;
     }
diff --git a/dbcon/mysql/ha_mcs_sysvars.cpp b/dbcon/mysql/ha_mcs_sysvars.cpp
index eb1c1c531..02f89ab50 100644
--- a/dbcon/mysql/ha_mcs_sysvars.cpp
+++ b/dbcon/mysql/ha_mcs_sysvars.cpp
@@ -98,6 +98,15 @@ static MYSQL_THDVAR_BOOL(
     1
 );
 
+static MYSQL_THDVAR_BOOL(
+    select_handler_in_stored_procedures,
+    PLUGIN_VAR_NOCMDARG,
+    "Enable/Disable the MCS select_handler for Stored Procedures",
+    NULL,
+    NULL,
+    1
+);
+
 static MYSQL_THDVAR_UINT(
     orderby_threads,
     PLUGIN_VAR_RQCMDARG,
@@ -332,6 +341,7 @@ st_mysql_sys_var* mcs_system_variables[] =
   MYSQL_SYSVAR(select_handler),
   MYSQL_SYSVAR(derived_handler),
   MYSQL_SYSVAR(group_by_handler),
+  MYSQL_SYSVAR(select_handler_in_stored_procedures),
   MYSQL_SYSVAR(orderby_threads),
   MYSQL_SYSVAR(decimal_scale),
   MYSQL_SYSVAR(use_decimal_scale),
@@ -419,6 +429,16 @@ void set_group_by_handler(THD* thd, bool value)
     THDVAR(thd, group_by_handler) = value;
 }
 
+bool get_select_handler_in_stored_procedures(THD* thd)
+{
+    return ( thd == NULL ) ? true :
+        THDVAR(thd, select_handler_in_stored_procedures);
+}
+void set_select_handler_in_stored_procedures(THD* thd, bool value)
+{
+    THDVAR(thd, select_handler_in_stored_procedures) = value;
+}
+
 void set_compression_type(THD* thd, ulong value)
 {
     THDVAR(thd, compression_type) = value;
diff --git a/dbcon/mysql/ha_mcs_sysvars.h b/dbcon/mysql/ha_mcs_sysvars.h
index ffb9f2fae..1bb01307f 100644
--- a/dbcon/mysql/ha_mcs_sysvars.h
+++ b/dbcon/mysql/ha_mcs_sysvars.h
@@ -62,6 +62,9 @@ void set_derived_handler(THD* thd, bool value);
 bool get_group_by_handler(THD* thd);
 void set_group_by_handler(THD* thd, bool value);
 
+bool get_select_handler_in_stored_procedures(THD* thd);
+void set_select_handler_in_stored_procedures(THD* thd, bool value);
+
 uint get_orderby_threads(THD* thd);
 void set_orderby_threads(THD* thd, uint value);